What Is DATA INDEPENDENCE? Also Describe Logical And Physical Data Independence?
The disjointing of data descriptions from the application programs (or user-interfaces) that uses the data is called data independence. Data independence is one o] the main advantages of DBMS. The three-schema architecture provides the concept of data independence, which means that upper-levels are unaffected by changes to lower-levels. The three schemas architecture makes it easier to achieve true data independence. There are two kinds of data independence. (i) Logical data independence (ii) Physical data independence Logical Data Independence: Logical data independence is the ability to modify the conceptual schema without having alteration in external schemas or application programs. Alterations in the conceptual schema may include addition or deletion of fresh entities, attributes or relationships and should be possible without having alteration to existing external schemas or having to rewrite application programs. Physical Data Independence: Physical data independence is the abil
